Determining Rates of Reactions - Text Questions

#1.
ORDER OF REACTION: the exponent value that describes the initial concentration of a specific reactant
OVERALL ORDER OF REACTIONS: the sum of the exponents in the reaction equation

#2.
i) Initial Concentration of SO2Cl2 --> 0.25 mol/L
Initial Rate of Reaction --> 3.5 x 10^-3 (0.0035) mol SO2Cl2/L(S)

ii) Initial Concentration of SO2Cl2 --> 0.50 mol/L
Initial Rate of Reaction --> 7.0 x 10^-3 (0.007) mol SO2Cl2/L(S)

#3.
a) r = k[NH4+(aq)][NO2-(aq)]
2.40 x 10^-7 (0.00000024) mol/(L)(S) = k [0.200mol/L][0.00500mol/L]
0.00000024 (mol^-1)(L^-1)(S^-1) = k [0.001 (mol^2)(L^-2)]
0.00024 (mol^-1)(L^1)(S^-1) = k

b) r = k[NH4+(aq)][NO2-(aq)]
r = 3.20 x 10^-4 (0.00032) L/mol(s) [0.100 mol/L][0.0150 mol/L]
r = 0.00032 L/mol(s) (0.0015 (mol^2)(L^-2))
r = 0.00000048 (L^3)(mol^-3)(S^-1)
r = 4.8 x 10^-7 (L^3)(mol^-3)(S^-1)

#4.
a) A --> 2^n = 4
n = 2
B --> 2^n = 2
n = 2
C --> 2^n = 1
n = 0

b) r = k [A]^2[B]^1[C]^0

#5.
a) If the temperature of the reaction increases, the reaction rate increases too
b) If the initial concentration of any reactant decreases, the reaction rate decreases too

#6.
i) TO DETERMINE THE EFFECT OF [A] ONA REACTION RATE, CONTROL [B] AND [C], USING TRIALS 1 AND 2

Trial 1: [A}(mol)(L^-1) --> 0.10
Rate Production (mol)(L^-1) --> 3.0 x 10^-4 (0.0003)
Trial 2: [A](mol)(L^-1) --> 0.20
Rate Production (mol)(L^-1) --> 1.2 x 10^-3 (0.0012)

Change Factor (a) = 2
Change Factor (b) = 4

RELATE CHANGE FACTORS BY AN EXPONENT
2^m = 4
m=2

therefore, R=k[A]^2[B]^n[C]^z

ii) TO DETERMINE THE EFFECT OF [B] ON A REACTION RATE, CONTROL [A] AD [C] USING TRIALS 1 AND 3

Trial 1: [B}(mol)(L^-1) --> 0.10
Rate Production (mol)(L^-1) --> 3.0 x 10^-4 (0.0003)
Trial 3: [B](mol)(L^-1) --> 0.30
Rate Production (mol)(L^-1) --> 3.0 x 10^-4 (0.0003)

Change Factor (a) = 3
Change Factor (b) = 1

RELATE CHANGE FACTORS BY AN EXPONENT
3^n = 1
n = 0

therefore, R=k[A]^2[B]^0[C]^z

iii) TO DETERMINE THE EFFECT OF [C] ON A REACTION RATE, CONTROL [A] AD [B] USING TRIALS 2 AND 4

Trial 2: [C](mol)(L^-1) --> 0.10
Rate Production (mol)(L^-1) --> 1.2 x 10^-3 (0.0012)
Trial 4: [C](mol)(L^-1) --> 0.20
Rate Production (mol)(L^-1) --> 2.4 x 10^-3 (0.0024)

Change Factor (a) = 2
Change Factor (b) = 2

RELATE CHANGE FACTORS BY AN EXPONENT
2^z = 2
z = 1

therefore, R=k[A]^2[B]^0[C]^1

iv) DETERMINING K (using Trial 1)

Rate = k [A]^2[B]^0[C]^1
3.0 x 10^-4 (0.0003) (mol)(L^-1)(S^-1) = k [0.10(mol)(L^-1)]^2[0.10(mol)(L^-1)]^0[0.10(mol)(L^-1)]^1
0.0003 (mol)(L^-1)(S^-1) = k (0.001) (mol^3)(L^-3)
k = 0.0003 (mol)(L^-1)(S^-1) / 0.001 (mol^3)(L^-3)
k = 0.3 (mol^-2)(L^2)(S^-1)

CALCULATING THE RATE OF PRODUCTION FOR X

R = k[A]^2[B]^0[C]^1
R = (0.3 (mol^-2)(L^2)(S^-1))[0.4 mol/L]^2[0.4 mol/L]^0[0.4 mol/L]^1
R = 0.0192 (mol^-5)(L^5)(S^-1)